Breathalyzer removes doubt from roadside readings

Unlike current colour change-based devices, this sensor would be reusable and could also provide a precise digital readout.

The new design is the said to be the first that uses the sensing properties of opal to detect ethanol, the intoxicating component of commercial liquor, by inducing a change in colour that is visible to the human eye. The research team describes their new method in a proof-of-concept paper published today in Optical Materials Express.

The portable breathalyzers used by roadside police use expensive electronic readouts, but these devices lack the ‘immediate and intuitive’ colour change that tells police whether the alcohol content of a suspect’s breath puts them in the legal red zone, said first author Riccardo Pernice of the Università degli Studi di Palermo in Italy.

Techniques that do use colour change to assess the level of alcohol concentration are typically less expensive, but they cannot give a precise reading of the alcohol concentration and most are used once before being disposed of. Pernice said his team’s proposed device combines the best elements of each of these two breathalyzer models.